Disclosed is a boat with at least one combustion engine positioned on or symmetrical with the vertical median plane of the boat and two engines provided symmetrical with respect to the vertical median plane, each including a propeller in a duct with: a central section on which the propeller is positioned, a rear section leading via a rear opening onto the transom of the hull, a front section with a continuous curved profile, leading via a side opening to the outside wall of the hull, the side opening having a larger cross-section than the cross-section of the rear opening in order for the duct to include at least one converging nozzle, the front section being oriented so that the stream of water exiting from the side opening is directed towards the front and forms an angle of 20 to 60 with respect to the wall of the hull.

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

A controller for a dynamic positioning system, the controller being configured to determine a position of a vessel relative to a target position and to control a propulsion system of the vessel based on the determined position of the vessel relative to the target position, wherein the controller is configured to monitor a property of at least part of a riser; and adjust the control of the propulsion system accordingly.

A method of dewatering a tailings lagoon retained by a dam comprising: excavating an excavation hole in the tailings lagoon; allowing water from surrounding tailings to enter the excavation hole; and pumping water in the excavation hole out of the excavation hole and discharging beyond a toe of the dam. Also disclosed is a method comprising: excavating a channel in a tailings lagoon from a shore of the tailings lagoon and floating a pontoon in water in the channel from the shore along the channel,wherein: excavating involves breaking down solid tailings in the tailings lagoon into a slurry using water and removing the slurry using a submersible slurry pump mounted on the pontoon.

Described is a robot (1) for cleaning swimming pools comprising a main body (2), a plurality of rotors (3), a control unit and means for cleaning the swimming pool.

The main body (2) has at least one sealed containment space (4).

The plurality of rotors (3) is configured for generating a hydrodynamic thrust designed for moving the robot inside an entire space of the swimming pool.

The control unit inserted in the containment space (4) and is configured for modifying at least one respective operating parameter of each rotor (3) in such a way as to direct the hydrodynamic thrust.

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

A method of controlling propulsion of a marine vessel includes receiving proximity measurements from one or more proximity sensors on the marine vessel and limiting user input authority over propulsion output in a direction of an object by at least one propulsion device based on the proximity measurement so as to maintain the marine vessel at least a buffer distance from the object. The method further includes suspending maintenance of the buffer distance from the object in response to a user-generated instruction. Then, when user control input is received via a user input device to move the marine vessel in the direction of the object, the at least one propulsion device is controlled based on the user control input such that the marine vessel approaches and impacts the object.

A system for controlling a marine vessel having first and second steering nozzles and corresponding first and second reversing buckets, comprises a processor configured to receive a first vessel control signal including at least a component corresponding to a translational thrust command in a port direction, and that is configured to provide a set of actuator control signals coupled to and control the first and second reversing buckets. The processor is configured to provide the set of actuator control signals so as to maintain the first reversing bucket substantially in a first discrete position and the second reversing bucket substantially in a second discrete position as long as the first vessel control signal includes a component corresponding to a translational thrust command in the port direction.